ASME B16.5 Flange DN550 / NPS 22
ASME B16.5 Flange DN550 / NPS 22
(OP)
Dear all forum member,
Can anyone enlighten me, why is it B16.5 do not have flange size of 22" ? I try to read through the B16.5 but still catch no ball. Thanks in advance.
Regards,
Wcw
Can anyone enlighten me, why is it B16.5 do not have flange size of 22" ? I try to read through the B16.5 but still catch no ball. Thanks in advance.
Regards,
Wcw





RE: ASME B16.5 Flange DN550 / NPS 22
Is this a rhetorical question or do you have an actual situation that requires a 22" flange?
Sometimes its possible to do all the right things and still get bad results
RE: ASME B16.5 Flange DN550 / NPS 22
I have an actual situation that require the use of 22" ASME Flange WNRF.
RE: ASME B16.5 Flange DN550 / NPS 22
Cheers,
gr2vessels
RE: ASME B16.5 Flange DN550 / NPS 22
See this for details as well. http://www.zmcsteel.com/PDF/Flange/ANSI%20Flange/A...
Why 16.5 doesn't list them? - Probably simply no call for them, but lots gets lost in history with these standards.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: ASME B16.5 Flange DN550 / NPS 22
My company recently received a job that require to use a 22" flange as manhole.
Horizontal Vessel, Combination is 22" WNRF Flange (manhole with davit) + 22" Shell + 22" Cap. (U-stamp required)
Normally in the drawing i will create a table of nozzle stating nozzle detail.
Example:
Item | Type | Rating | Size | Qty |
N1 | ASME B16.5 | CL300 | DN200 | 2 |
How about "Type" for this case? Is it like:
Item | Type | Rating | Size | Qty |
N1 | ASME B16.5 | CL300 | DN200 | 2 |
M1 | MSS SP44 | CL300 | DN550 | 1 |
RE: ASME B16.5 Flange DN550 / NPS 22
With vessels you need to be a little more careful and you could ask a similar question in the pressure vessels forum and get a different answer(!) I don't know how ASME VIII treats MSS SP-44.
A 22" manhole is normally regarded as being too small (min 24" and 30" is better. Can't you just use a 24" one instead?? I've entered vessels via 24" and it is a real squeeze - and I'm not that fat(!!)
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: ASME B16.5 Flange DN550 / NPS 22
Point still remains though - Can't you substitute a 24" pipe and flange?
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: ASME B16.5 Flange DN550 / NPS 22
They are frequently specified by "Value Engineers" (MBAs who try to keep the cost down) who blame others at the end of the job.
24 inch manways are a good choice.... but don't forget a divot and associated hardware to enable maintenance to get the cover out of the way. Allow space in the layout drawing to show the "pivot of the divot"
http://www.standardequipmentclosures.com/manholes....
MJCronin
Sr. Process Engineer
RE: ASME B16.5 Flange DN550 / NPS 22
The manhole for this vessel is for user to replace the filter elements only ( as long as hand is reachable to the filter element to do some tighten/un-tighten and removing works of the element) is sufficient). The 22" is the design size to fit enough filter element into the vessel.
I saw some internet source that they got sell ASME B16.5 22" flange! example: texas flange http://www.texasflange.com/images/Catalog/catalog-...
Is it valid for them to classify their flange as B16.5 for the size of 22" when B16.5 do not have any 22" flange.
RE: ASME B16.5 Flange DN550 / NPS 22
You would need to ask them how they would certify / sell these flanges and maybe they've just used the MSS-SP44 dimensions?
Interestingly though in some pages, e.g. page 14 bolt lengths, 22" suddenly disappears(!). Let us know what they say.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way